Characterization of Pullulan/Chitosan Oligosaccharide/Montmorillonite Nanofibers Prepared by Electrospinning Technique.

Pullulan/Chitosan oligosaccharide (COS)/Montmorillonite (MMT) hybrid nanofibers were electrospun from their aqueous solution using different Pullulan/COS mass ratios and variable amounts of MMT. The effects of Pullulan/COS mass ratios and MMT contents on the morphologies and properties of PulluIan/COS/MMT hybrid nanofibers were investigated. The obtained nanofibers were characterized with field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermo gravimetric analysis (TGA), and tensile strength measurement. The Pullulan/COS mass ratio and MMT contents significantly influence the morphologies and properties of the Pullulan/COS/MMT hybrid nanofibers. Higher Pullulan contents than COS contents forms uniform and bead free nanofibers. The addition of COS to Pullulan improves the thermal stability of Pullulan/COS blend nanofibers. The incorporation of MMT to the Pullulan/COS/MMT hybrid nanofibers increase their fiber diameter, improves their thermal stability and tensile strength. These morphological changes and property enhancement depend on the amount of MMT added. The XRD and TEM results suggest the coexistence of Pullulan, COS and MMT within polymer matrix through intercalation of polymer chain between silicate layers forming well-ordered multiplayer morphology with alternating polymeric and silicate layers.

Optimum Conditions for the Fabrication of Zein/Ag Composite Nanoparticles from Ethanol/H2O Co-Solvents Using Electrospinning.

The optimum conditions for the fabrication of zein/Ag composite nanoparticles from ethanol/H2O cosolvents using electrospinning and the properties of the composite were investigated. The zein/Ag nanoparticles were characterized using field-emission scanning electron microscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric analysis. The antibacterial activity of the zein/Ag composite nanoparticles was also investigated. The XRD patterns and TEM images indicate the coexistence of a zein matrix and well-distributed Ag nanoparticles.

Novel preparation and characterization of human hair-based nanofibers using electrospinning process.

Human hair-based biocomposite nanofibers (NFs) have been fabricated by an electrospinning technique. Aqueous keratin extracted from human hair was successfully blended with poly(vinyl alcohol) (PVA). The focus here is on transforming into keratin/PVA nanofibrous membranes and insoluble property of electrospun NFs. The resulting hair-based NFs were characterized using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning colorimetry (DSC), and thermogravimetric analysis (TGA). Toward the potential use of these NFs after cross-linking with various weight fractions of glyoxal, its physicochemical properties, such as morphology, mechanical strength, crystallinity, and chemical structure were investigated. Keratin/PVA ratio of 2/1 NFs with 6 wt%-glyoxal showed good uniformity in fiber morphology and suitable mechanical properties, and excellent antibacterial activity providing a potential application of hair-based NFs in biomedical field.

Characterization of carbon nanotube-cdse hybrid nanomaterials.

MWNT-CdSe hybrid nanomaterials were prepared with carboxylic acid-treated CdSe nanoparticles and amino-functionalized MWNTs. The hybridization of MWNT-CdSe nanomaterials was performed by the formation of covalent bond between MWNT and CdSe. Their covalent bond lengths were varied with changing the linking spacers. Amino-functionalized MWNTs were reacted with CdSe nanoparticles which were functionalized with carboxylic acid groups. Their detailed structures were characterized by FT-IR, XPS, and small angle X-ray scattering. Through small angle X-ray scattering experiments, it was found that the structures of CdSe nanoparticles were not regular, and their sizes were broadly distributed in solution. The longer amino-functionalized MWNTs were thermally decomposed at lower temperature. The photoluminescence (PL) of chemically-linked MWNT-CdSe hybrid nanomaterials were weaker than that of CdSe nanoparticles. In addition, their PL intensities more weakened on the MWNT-CdSe with the longer spacers.

Characterization of attractive interaction-driven carbon nanotube composites with Cd-based nanoparticles.

Multiwalled carbon nanotube (MWNT) composites with cadmium telluride (CdTe) or cadmium selenide (CdSe) nanoparticles were prepared via electrostatic interaction. The MWNTs were modified with carboxylic acid groups. Both the CdTe and CdSe nanoparticles were stabilized with 2-(dimethylamino) ethanethiol hydrochloride to develop positive charges on their surfaces in water. They were characterized in detail via UV-visible spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The energy state of the MWNTs was significantly modified by the electrostatic binding between the nanoparticles and carboxylated MWNTs, resulting in absorption at approximately 250 nm. XPS analysis also proved the electronic redistribution of the nanoparticles and the MWNTs. The binding energies of the elements Cd, Se, and Te were definitely changed by the attractive interaction between the nanoparticles and the MWNTs. The distribution of the CdTe or CdSe nanoparticles and the morphologies of the MWNT composites were deliberately investigated from TEM images and XRD.